 /*******************************************************************************
  * Copyright (c) 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  ******************************************************************************/

 package org.eclipse.core.databinding.conversion;

 import java.math.BigDecimal ;
 import java.math.BigInteger ;

 import org.eclipse.core.internal.databinding.conversion.StringToNumberParser;
 import org.eclipse.core.internal.databinding.conversion.StringToNumberParser.ParseResult;
 import org.eclipse.core.internal.databinding.validation.NumberFormatConverter;

 import com.ibm.icu.text.NumberFormat;

 /**
  * Converts a String to a Number using <code>NumberFormat.parse(...)</code>.
  * This class is thread safe.
  *
  * @since 1.0
  */
 public class StringToNumberConverter extends NumberFormatConverter {
     private Class toType;
     /**
      * NumberFormat instance to use for conversion. Access must be synchronized.
      */
     private NumberFormat numberFormat;

     /**
      * Minimum possible value for the type. Can be <code>null</code> as
      * BigInteger doesn't have bounds.
      */
     private final Number min;
     /**
      * Maximum possible value for the type. Can be <code>null</code> as
      * BigInteger doesn't have bounds.
      */
     private final Number max;

     /**
      * The boxed type of the toType;
      */
     private final Class boxedType;

     private static final Integer MIN_INTEGER = new Integer (Integer.MIN_VALUE);
     private static final Integer MAX_INTEGER = new Integer (Integer.MAX_VALUE);

     private static final Double MIN_DOUBLE = new Double (-Double.MAX_VALUE);
     private static final Double MAX_DOUBLE = new Double (Double.MAX_VALUE);

     private static final Long MIN_LONG = new Long (Long.MIN_VALUE);
     private static final Long MAX_LONG = new Long (Long.MIN_VALUE);

     private static final Float MIN_FLOAT = new Float (-Float.MAX_VALUE);
     private static final Float MAX_FLOAT = new Float (Float.MAX_VALUE);

     /**
      * @param numberFormat
      * @param toType
      * @param min
      * minimum possible value for the type, can be <code>null</code>
      * as BigInteger doesn't have bounds
      * @param max
      * maximum possible value for the type, can be <code>null</code>
      * as BigInteger doesn't have bounds
      * @param boxedType
      * a convenience that allows for the checking against one type
      * rather than boxed and unboxed types
      */
     private StringToNumberConverter(NumberFormat numberFormat, Class toType,
             Number min, Number max, Class boxedType) {
         super(String .class, toType, numberFormat);

         this.toType = toType;
         this.numberFormat = numberFormat;
         this.min = min;
         this.max = max;
         this.boxedType = boxedType;
     }

     /**
      * Converts the provided <code>fromObject</code> to the requested
      * {@link #getToType() to type}.
      *
      * @see org.eclipse.core.databinding.conversion.IConverter#convert(java.lang.Object)
      * @throws IllegalArgumentException
      * if the value isn't in the format required by the NumberFormat
      * or the value is out of range for the
      * {@link #getToType() to type}.
      * @throws IllegalArgumentException
      * if conversion was not possible
      */
     public Object convert(Object fromObject) {
         ParseResult result = StringToNumberParser.parse(fromObject,
                 numberFormat, toType.isPrimitive());

         if (result.getPosition() != null) {
             // this shouldn't happen in the pipeline as validation should catch
 // it but anyone can call convert so we should return a properly
 // formatted message in an exception
 throw new IllegalArgumentException (StringToNumberParser
                     .createParseErrorMessage((String ) fromObject, result
                             .getPosition()));
         } else if (result.getNumber() == null) {
             // if an error didn't occur and the number is null then it's a boxed
 // type and null should be returned
 return null;
         }

         /*
          * Technically the checks for ranges aren't needed here because the
          * validator should have validated this already but we shouldn't assume
          * this has occurred.
          */
         if (Integer .class.equals(boxedType)) {
             if (StringToNumberParser.inIntegerRange(result.getNumber())) {
                 return new Integer (result.getNumber().intValue());
             }
         } else if (Double .class.equals(boxedType)) {
             if (StringToNumberParser.inDoubleRange(result.getNumber())) {
                 return new Double (result.getNumber().doubleValue());
             }
         } else if (Long .class.equals(boxedType)) {
             if (StringToNumberParser.inLongRange(result.getNumber())) {
                 return new Long (result.getNumber().longValue());
             }
         } else if (Float .class.equals(boxedType)) {
             if (StringToNumberParser.inFloatRange(result.getNumber())) {
                 return new Float (result.getNumber().floatValue());
             }
         } else if (BigInteger .class.equals(boxedType)) {
             return new BigDecimal (result.getNumber().doubleValue())
                     .toBigInteger();
         }

         if (min != null && max != null) {
             throw new IllegalArgumentException (StringToNumberParser
                     .createOutOfRangeMessage(min, max, numberFormat));
         }

         /*
          * Fail safe. I don't think this could even be thrown but throwing the
          * exception is better than returning null and hiding the error.
          */
         throw new IllegalArgumentException (
                 "Could not convert [" + fromObject + "] to type [" + toType + "]"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 }

     /**
      * @param primitive
      * <code>true</code> if the convert to type is an int
      * @return to Integer converter for the default locale
      */
     public static StringToNumberConverter toInteger(boolean primitive) {
         return toInteger(NumberFormat.getIntegerInstance(), primitive);
     }

     /**
      * @param numberFormat
      * @param primitive
      * @return to Integer converter with the provided numberFormat
      */
     public static StringToNumberConverter toInteger(NumberFormat numberFormat,
             boolean primitive) {
         return new StringToNumberConverter(numberFormat,
                 (primitive) ? Integer.TYPE : Integer .class, MIN_INTEGER,
                 MAX_INTEGER, Integer .class);
     }

     /**
      * @param primitive
      * <code>true</code> if the convert to type is a double
      * @return to Double converter for the default locale
      */
     public static StringToNumberConverter toDouble(boolean primitive) {
         return toDouble(NumberFormat.getNumberInstance(), primitive);
     }

     /**
      * @param numberFormat
      * @param primitive
      * @return to Double converter with the provided numberFormat
      */
     public static StringToNumberConverter toDouble(NumberFormat numberFormat,
             boolean primitive) {
         return new StringToNumberConverter(numberFormat,
                 (primitive) ? Double.TYPE : Double .class, MIN_DOUBLE,
                 MAX_DOUBLE, Double .class);
     }

     /**
      * @param primitive
      * <code>true</code> if the convert to type is a long
      * @return to Long converter for the default locale
      */
     public static StringToNumberConverter toLong(boolean primitive) {
         return toLong(NumberFormat.getIntegerInstance(), primitive);
     }

     /**
      * @param numberFormat
      * @param primitive
      * @return to Long converter with the provided numberFormat
      */
     public static StringToNumberConverter toLong(NumberFormat numberFormat,
             boolean primitive) {
         return new StringToNumberConverter(numberFormat,
                 (primitive) ? Long.TYPE : Long .class, MIN_LONG, MAX_LONG,
                 Long .class);
     }

     /**
      * @param primitive
      * <code>true</code> if the convert to type is a float
      * @return to Float converter for the default locale
      */
     public static StringToNumberConverter toFloat(boolean primitive) {
         return toFloat(NumberFormat.getNumberInstance(), primitive);
     }

     /**
      * @param numberFormat
      * @param primitive
      * @return to Float converter with the provided numberFormat
      */
     public static StringToNumberConverter toFloat(NumberFormat numberFormat,
             boolean primitive) {
         return new StringToNumberConverter(numberFormat,
                 (primitive) ? Float.TYPE : Float .class, MIN_FLOAT, MAX_FLOAT,
                 Float .class);
     }

     /**
      * @return to BigInteger converter for the default locale
      */
     public static StringToNumberConverter toBigInteger() {
         return toBigInteger(NumberFormat.getIntegerInstance());
     }

     /**
      * @param numberFormat
      * @return to BigInteger converter with the provided numberFormat
      */
     public static StringToNumberConverter toBigInteger(NumberFormat numberFormat) {
         return new StringToNumberConverter(numberFormat, BigInteger .class,
                 null, null, BigInteger .class);
     }
 }

